fig10
Figure 10. XRD patterns of the raw, alkali-pretreated, and alkali-pretreated, acid-leached coal wastes of the (A) Western Kentucky No. 13 and (B) Fire Clay seams. (Alkali pretreatment conditions: 5 M NaOH at 90 °C; acid leaching conditions: 1.2 M HCl at 90 °C). XRD: X-ray diffraction.
